In an existing display panel, the display panel is lighted up usually by a signal supplied via a test point. It is very different from directly using the module to light up the display panel by supplying a signal via a printed circuit board. The strength of the supplied signal in using the test point to supply signal to light up the display panel is apparently not as strong as that of the supplied signal in using the printed circuit board to supply signal. Moreover, the connection path is much longer, the load is much heavier, and the degradation of the signal is much faster. Therefore, the data signals supplied to the display panel for a test are generally leading to a positive frame in a direct current or are a low frequency signal. In this way, the signal is not distorted too much after arrives the pixel on the display panel so that the display panel can be normally lighted up for defect inspection.
In performing a test on an inversion design of pixel structure of the panel, if a signal of a positive frame in a direct current is directly supplied to a red, green, or blue test point, a screen of mixed color by red plus green, or green plus blue, or blue plus red will be lighted up. However, it is difficult to detect the defects such as bright and dark lines, color resistant defects, and red/green/blue uniform colors using the screen of mixed color. If the subject to be inspected is not a GOA (Gate Driver on Array) product, one can connect the gate electrodes of odd row together and then the even row together, turn on the gate electrodes of odd row to supply a low frequency signal of a positive frame to red test points, and then turn on the gate electrodes of even row to supply a low frequency signal of a positive frame to green test points so as to light up a red screen. However, for a GOA product, each row of gate electrodes corresponds to an output scan signal of each unit in a GOA electric circuit. The regular timing of GOA signals cannot carry out connecting the gate lines of odd row and even row individually as the same as the non-GOA product does. Therefore, for the GOA product, it is hard to light up a pure color screen of red, green, or blue color for the defect inspection on the display panel.
Above all, in inspecting a screen of a GOA display panel in the existing skills, a screen of mixed colors of red plus green, or green plus blue, or blue plus red will appear when a module is used to inspect a screen of a pure color and turn on the same via a printed circuit board, and therefore the dead pixel on the screen cannot be accurately detected.